BUILT_PRODUCTS_DIR doesn't work in sources section

[kmlmsg]

I'm trying to add copyFiles build phase but it returns spec validation error: Spec validation error: Target "*target*" has a missing source directory "/Users/*user*/Documents/Projects/*folder*/*folder*/*folder*/*folder*/BUILT_PRODUCTS_DIR/AutoStart"

    sources:
      - path: $(BUILT_PRODUCTS_DIR)/AutoStart
        buildPhase:
          copyFiles:
            destination: wrapper
            subpath: Contents/Library/LoginItems

Am I doing something wrong?

[kmlmsg]

Nevermind, I used SMAppService.mainApp.register() instead of helper app.